refactor: redesign the image structure and related code

[fuweid]

Ⅰ. Issue Description

There is gap between oci/pouch image structure and docker image information, which we need to verify. After that, we need to improve the information convertor code to make the code clear.

Ⅱ. Describe what happened

None

Ⅲ. Describe what you expected to happen

The user can use pouch image related command or API

Ⅳ. How to reproduce it (as minimally and precisely as possible)

Ⅴ. Anything else we need to know?

For the CRI part, it maybe involve @YaoZengzeng in reviewing code or design.

Ⅵ. Environment:

• pouch version (use pouch version):
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others:

[fuweid]

Fixed by #1267